Many functions of modern devices in automotive, consumer and industrial applications, such as converting electrical energy and driving an electric motor or an electric machine, rely on semiconductor devices. For example, Insulated Gate Bipolar Transistors (IGBTs), Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) and diodes, to name a few, have been used for various applications including, but not limited to switches in power supplies and power converters.
Often, a power semiconductor device comprises a plurality of transistor cells and deep semiconductor well regions arranged external of the transistor cells.
For example, such a deep semiconductor well region may be a floating semiconductor region having dop ants of the same conductivity type as a body region of each transistor cell. The purpose of such a floating semiconductor well region can be, e.g., carrier flooding during operation of the semiconductor device or protection a bottom of a gate trench of each transistor cell.
Further, a semiconductor well region that is electrically connected with a source contact of the semiconductor device can be arranged in an edge zone of the semiconductor device. For example, the semiconductor well region in the edge zone surrounds the transistor cells being arranged in an active zone. Such a structure may be provided for diverting currents in the vicinity of edges of the semiconductor device. For example, such a structure may be provided for diverting a hole current during a switch-off process of the semiconductor device.